Recently, color images are widely spread, and higher image quality has been increasingly demanded. In digital full color copiers and printers, a color image manuscript is subjected to color separation with filters of blue, green, and red, and latent images corresponding to the original image are developed with developers of magenta, magenta, cyan, and black. For this reason, the colorants in the developers of the respective colors give a great influence to image quality. Usually, in the case where a pigment is dispersed in a variety of media, it is difficult to form a sufficiently fine pigment or to uniformly disperse the pigment.
In the color toners, the magenta toner is important in reproduction of a skin color. Further, the color tone of the skin in a human figure is a halftone. Accordingly, high developing properties are also demanded. As a colorant for a magenta toner, quinacridone colorants, thioindigo colorants, xanthene colorants, monoazo colorants, perylene colorants, and diketopyrrole colorants are known.
In the case where a dye is used in the colorant for magenta, the dye demonstrates a vivid magenta color in the initial period. The dye, however, has low lightfastness, and color nuance greatly changed after the dye is left. Moreover, in the case of a light color, a bright and sharp image is obtained. In a region of a dark color, however, a sufficient image density is difficult to obtain. Particularly, in the case where the colors are mixed and a dark red color and a dark blue color are reproduced, the range of the color to be reproduced is likely to be narrower. The xanthene colorant is a colorant having good color reproducibility and color tone, but the lightfastness is significantly reduced when the colorant is used in a liquid form. Accordingly, various measures are needed (see Patent Literatures 1 and 2). These magenta colorants have good affinity with a binder resin and high lightfastness, and provide a magenta toner having high frictional charging properties and an excellent color tone. In order to satisfy transparency and provide an image closer to the manuscript, however, a magenta toner having further improved color tone, saturation, and electrophotographic properties is strongly desired.